Numerical simulation on stress relief processes using and extended thermo-elastic-plastic FEM

摘要

In this paper, an extended thermo-elastic-plastic FEM system is proposed, and its application to stress relief annealing processes of bent specimens is shown. The FEM system is constructed by introducing a new constitutive equation, that includes the generalized deformation energy as an internal variable, into the ABAQUS code. In the system, elastic-plastic analysis and thermal analysis are combined, and distrotion of the specimen and temperature distribution are determined simultaneously. A new calculation method to compensate thermal stress in the thickness direction that arises when a conventional plane strain element is applied to a heat-treatment process is also proposed. The FEM system was applied to three-point-bending and annealing processes. The results agreed qualitatively with experimental ones. Based on the simulation results, this paper discusses mechanisms of stress relief annealing.